Paper products such as facial tissues, paper towels, bath tissues, napkins and other similar products, are designed to include several important properties. For example, products should have good bulk, good absorbency, a soft feel, and should have good strength and durability. Unfortunately, when steps are taken to increase one property of the product, other characteristics of the product are often adversely affected.
Formulators have, for years, attempted to balance a higher level of softwood fibers in their paper structures to obtain adequate or improved strength of their structures while at the same time trying to minimize the negative impact on softness, durability or absorbency generally resulting from higher levels of softwood fibers. The problem has been that formulators have been unable to reliably make acceptable fibrous structures, especially through-air-dried (“TAD”) sanitary fibrous tissue structures that contain less than 20% by weight softwood fibers on a dry fiber basis without the need to excessively refine the softwood fibers and/or add excessive chemical strength agents to achieve the desired level of strength and/or reliability (avoid sheet breaks during making and/or processing).
For multi-use fibrous sheets used for example for paper toweling, napkins and hankies in particular, increased softwood content, increased refining and cationic/anionic polymer addition is required to achieve strength targets required for durability requirements. However, all of these actions can negatively affect the sheet feel and product absorbency.
Accordingly there continues to be a need for a new fibrous paper structure that further optimizes the physical product performance of tissue products that increase wet and dry strength without sacrificing softness, absorbency and paper making reliability. Such structures are especially valuable for multi-density paper making structures with non-limiting examples of such structures being through air dried, NTT, ATMOS and UCTAD processes.